During October 2012 to July 2014, the research team of Dr. Xiao-Hua Zhu in our laboratory successfully carried out the first Chinese PIES (pressure-recording inverted echo sounder) observation in the northern South China Sea. The observation section is located in the region southeast of Hainan Island, along the 114th altimeter track (Fig.1). The goal of the observation was to obtain the spatial structure and temporal variation of the South China Sea western boundary current across the section. Based on the PIES observation, the research team precisely estimated the temperature, salinity and velocity structure and variability via GEM (Gravest Empirical Mode), and calculated the volume transport time series (VTPIES) during the observation. Because of a strong linear relationship exists between VTPIES and the sea surface height difference (SSHD) across the observational section, the research team further estimated the volume transport of the South China Sea western boundary current (VTNSCS) since the year of 1992. The VTNSCS data is published and updated regularly on this website to achieve the near-real-time monitoring of the South China Sea western boundary current.

Figure 1. Left Panel: Location map of the PIES stations. Red triangles indicate the individual PIES instruments and blue dots indicate the TOPEX/POSEIDON and Jason-1/2 satellite altimeter track (track 114). Bathymetry is contoured in meters. Right Panel: The location and bathymetry of the PIES observational section, the black line indicates the bottom topography.

[24] Yuan Yaochu, Zhu Xiao-Hua, Zhou Feng. 2015. Progress of studies in China from July 2010 to May 2015 on the influence of the Kuroshio on neighboring Chinese seas and the Ryukyu Current. Acta Oceanologica Sinica, 34(12): 1–10, doi: 10.1007/s13131-015-0771-z